A reconfigurable non-linear active metasurface for coherent wave down-conversion

Metasurfaces can manipulate the amplitude and phase of electromagnetic waves, offering applications from antenna design and cloaking to imaging and communication. Temporal and non-linear metasurfaces can also adjust the frequency of impinging waves, advancing frequency conversion, sensing, and quantum systems. Here, we demonstrate a non-linear active electronic-photonic metasurface that transfers information from an impinging optical wave to a millimeter-wave beam. The proof-of-concept metasurface is designed to radiate a steerable 28 GHz beam when illuminated with an optical wave at 193 THz and consists of optically synchronized electronic-photonic chips tiled on a printed circuit board containing a microstrip patch antenna array. Light, modulated with a data-encoded mm-wave carrier, is coupled into electronic-photonic chips using microlenses. Within each chip, the mm-wave signal is detected, phased adjusted, amplified, and routed to an off-chip antenna. Beam-steering over a range of 60° in elevation and azimuth and data transmission at 2 Gb/s over a fiber-wireless link are demonstrated.